Scene backgrounds paint reliably on the web

Scene backgrounds — the sky, mid, and foreground layers of walking and story scenes, plus the fight-field biome — could come up blank on the web, sometimes flat green (the app's root color) or black. They now render through the same image path the character sprites already used, and stay painted through scrolling and step changes.

Exiting a battle scene could occasionally never complete — the exit action would fire but the transition wouldn't finish. The exit path now finishes reliably.

The F&F welcome popup now checks connection quality when you land. If the connection isn't stable enough to play well, the popup surfaces a warning so you're not left wondering why the first fight is loading slowly.